Consumers are increasingly demanding data services on mobile wireless communication devices, such as cell phones. For example, streaming video is a fun and useful new application for cell phones. One application of streaming video is broadcast video. Broadcast means that data is sent to many users simultaneously. For example, a video movie may be broadcast from a cellular base station to many cell phone users.
One problem with streaming video applications and other similar applications is that they require much more bandwidth than traditional voice calls. The increased bandwidth requirements tend to overload network resources. Additionally, different users have different air link conditions. A user with poor coverage may not successfully receive and decode as much of the data sent as some other users within the same broadcast area.
The user with poor channel conditions may be known in advance or not known in advance.